1. Field of the Invention
The present invention relates to an indicator of a vehicle. More specifically, the present invention relates to an indicator that makes a vehicle more visible from a surrounding area even in an adverse condition, such as thick fog or heavy rain.
2. Description of Relevant Art
Conventionally, an indicator, by which a surrounding area (other vehicles, pedestrians etc.) is notified of the existence or information (moving directions etc.) of a vehicle, has been provided on the vehicle.
As examples of the indicator, a rear fog lamp, a width indicator, a number-plate light, a taillight, a parking light, a brake light, a direction indicator, and a hazard indicator can be cited.
These kinds of indicators have to be visible from a surrounding area, especially, even in the adverse condition, such as thick fog or heavy rain.
As an example of these kinds of indicator, a brake light disclosed in Japanese unexamined patent publication JP H08-127297 has been discovered (see Page 1 and 2, FIG. 1).
In this Japanese unexamined patent publication, a brake light composed of a plurality of LED lamps and clear beads, which are provided in the bumper made of a clear or diaphanous synthetic resin, is disclosed. In this brake light, the visibility of the brake light is improved by scattering the light emitted from respective LED lamps using clear beads.
In the conventional indicator, such as the indicator disclosed in Japanese unexamined patent publication, however, un-polarized light is emitted from a light source. Un-polarized light tends to be diffused in a horizontal direction and a perpendicular direction with respect to the ground. Since un-polarized light is widely diffused under the adverse condition, such as in a thick fog or a heavy rain, the contour of the vehicle is obscured and thus the visibility of the vehicle from a surrounding area becomes worse. In other words, since the contour of the vehicle becomes unclear when the vehicle is looked from a surrounding area, the presence of the vehicle is not accurately recognized from a surrounding area.
In particular, in case of the rear fog lamp, as shown in FIG. 9A, since un-polarized light emitted from respective rear fog lamps 40A and 40B are diffused in a horizontal direction and a perpendicular direction with respect to a ground, the contour of the vehicle V is obscured when the vehicle V is looked from a surrounding area. Thus, the width of the vehicle V, and the distance from a following vehicle to the vehicle V cannot be recognized by the following vehicle correctly.
In case of the indicator used as width indicator, as show in FIG. 10A, since un-polarized light emitted from respective width indicators 50A and 50B is diffused in a horizontal direction and a perpendicular direction with respect to a ground, the contour of the vehicle V is obscured when the vehicle V is looked from a surrounding area. Thus, the width of the vehicle V, and the distance from the oncoming vehicle to the vehicle V cannot be recognized by the oncoming vehicle correctly.
Therefore, there has been required an indicator that can be recognized in an adverse condition, such as thick fog or heavy rain, and that enables the existence of the vehicle adopting the indicator be recognized in a surrounding area.